New York Gov. Andrew Cuomo (D) announced on Sunday that the state—the epicenter of the COVID-19 pandemic—would be rolling out “aggressive” antibody testing to help verify how many residents have been infected amid efforts to reopen the state.

Stating that they don’t really know many people have been infected by coronavirus but have since recovered, since they don’t have antibody testing on a large scale, the governor said they’re now “going to do that in the most aggressive way in the nation.” He went on to claim that the state would test thousands of people to find out what percent of the population may “at least be short-term immune to the virus.”

While Cuomo insists this will give them a “true snapshot” of what they’re dealing with, there are questions about the accuracy of the current antibody tests, many of which are being made in China without FDA approval, and as the World Health Organization warned Friday that there's no evidence that antibodies confer immunity from the coronavirus.